Analysis of xx-top500-105-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .9..7..2.....3.6..............5.1.9.3.....8.76........8.....3...5.9........4..... initial

Autosolve

position: .93675.28.8.13967..6.84293..78561.933152948676.9387...8..7.63.9.5.9.3.8.93.4.8... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A8: 1,4 => CTR => A8: 2,7
* DIS # A2: 2,4 => CTR => A2: 5
* PRF # A2: 5 => SOL
* DIS # C7: 2,4 => CTR => C7: 1
* PRF # A3: 1,7 => SOL
* DIS # A3: 5 => CTR => A3: 1,7
* DIS # C8: 1,7 => CTR => C8: 2,4,6
* DIS # C9: 1,7 => CTR => C9: 2,6
* DIS # G6: 1,4 => CTR => G6: 2,5
* DIS # G8: 1,4 => CTR => G8: 2,7
* PRF # A2: 4,5 => SOL
* DIS # A2: 2 => CTR => A2: 4,5
* DIS # A3: 7 => CTR => A3: 1,5
* DIS # A2: 2,4 => CTR => A2: 5
* PRF # A2: 5 => SOL
* DIS # A8: 2,4 => CTR => A8: 1,7
* DIS # G6: 2,4 => CTR => G6: 1,5
* PRF # I6: 2,4 => SOL
* DIS # I6: 1 => CTR => I6: 2,4
* DIS # G6: 2,4 => CTR => G6: 1,5
* PRF # I6: 2,4 => SOL
* DIS # I6: 1 => CTR => I6: 2,4
* PRF # G8: 2,4 => SOL
* DIS # C7: 2,4 => CTR => C7: 1
* DIS # A8: 2,4 => CTR => A8: 1,7
* DIS # E7: 1,2 => CTR => E7: 5
* DIS # A8: 1,2 => CTR => A8: 4,7
* DIS # C8: 1,2 => CTR => C8: 4,6,7
* DIS # I8: 1,2 => CTR => I8: 4,6
* DIS # H7: 1,5 => CTR => H7: 4
* PRF # H7: 4 => SOL
* DIS # G9: 1,5 => CTR => G9: 2,7
* PRF # E9: 2 => SOL
* PRF # H6: 1,5 => SOL
* DIS # H6: 4 => CTR => H6: 1,5
* CNT  35 HDP CHAINS /  58 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* DIS # A8: 1,4 => CTR => A8: 2,7
* DIS A8: 2,7 # A2: 2,4 => CTR => A2: 5
* PRF A8: 2,7 + A2: 5 => SOL
* STA A8: 2,7 + A2: 5
* CNT   3 HDP CHAINS /   2 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Details

Positions

.9..7..2.....3.6..............5.1.9.3.....8.76........8.....3...5.9........4..... initial
.93675.28.8.13967..6.84293..78561.933152948676.9387...8..7.63.9.5.9.3.8.93.4.8... autosolve
493675128582139674167842935278561493315294867649387512821756349754913286936428751 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
A1: 1,4
C2: 2,4
C3: 1,7
G1: 1,4
I2: 4,5
I3: 1,5
A4: 2,4
B6: 2,4
G4: 2,4
B7: 2,4
E8: 1,2
H9: 1,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
G1,I3: 1.. / G1 = 1  =>  0 pairs (*) / I3 = 1  =>  0 pairs (X)
A1,G1: 1.. / A1 = 1  =>  0 pairs (X) / G1 = 1  =>  0 pairs (_)
A2,C2: 2.. / A2 = 2  =>  0 pairs (X) / C2 = 2  =>  0 pairs (_)
A4,B6: 2.. / A4 = 2  =>  0 pairs (*) / B6 = 2  =>  0 pairs (X)
A4,G4: 2.. / A4 = 2  =>  0 pairs (*) / G4 = 2  =>  0 pairs (X)
B6,B7: 2.. / B6 = 2  =>  0 pairs (X) / B7 = 2  =>  0 pairs (_)
G1,I2: 4.. / G1 = 4  =>  0 pairs (X) / I2 = 4  =>  0 pairs (_)
A4,B6: 4.. / A4 = 4  =>  0 pairs (X) / B6 = 4  =>  0 pairs (_)
A1,G1: 4.. / A1 = 4  =>  0 pairs (*) / G1 = 4  =>  0 pairs (X)
A4,G4: 4.. / A4 = 4  =>  0 pairs (X) / G4 = 4  =>  0 pairs (_)
B6,B7: 4.. / B6 = 4  =>  0 pairs (*) / B7 = 4  =>  0 pairs (X)
H6,H7: 4.. / H6 = 4  =>  0 pairs (X) / H7 = 4  =>  0 pairs (_)
A2,A3: 5.. / A2 = 5  =>  0 pairs (*) / A3 = 5  =>  0 pairs (X)
I2,I3: 5.. / I2 = 5  =>  0 pairs (X) / I3 = 5  =>  0 pairs (_)
G6,H6: 5.. / G6 = 5  => 13 pairs (_) / H6 = 5  =>  0 pairs (X)
E7,E9: 5.. / E7 = 5  => 14 pairs (_) / E9 = 5  =>  0 pairs (X)
A2,I2: 5.. / A2 = 5  =>  0 pairs (*) / I2 = 5  =>  0 pairs (X)
A3,I3: 5.. / A3 = 5  =>  0 pairs (X) / I3 = 5  =>  0 pairs (_)
E7,H7: 5.. / E7 = 5  => 14 pairs (_) / H7 = 5  =>  0 pairs (X)
G6,G9: 5.. / G6 = 5  => 13 pairs (_) / G9 = 5  =>  0 pairs (X)
C8,C9: 6.. / C8 = 6  => 12 pairs (_) / C9 = 6  => 14 pairs (_)
I8,I9: 6.. / I8 = 6  => 14 pairs (_) / I9 = 6  => 12 pairs (_)
C8,I8: 6.. / C8 = 6  => 12 pairs (_) / I8 = 6  => 14 pairs (_)
C9,I9: 6.. / C9 = 6  => 14 pairs (_) / I9 = 6  => 12 pairs (_)
A3,C3: 7.. / A3 = 7  =>  0 pairs (X) / C3 = 7  => 13 pairs (_)
G8,G9: 7.. / G8 = 7  =>  0 pairs (X) / G9 = 7  => 13 pairs (_)
C9,G9: 7.. / C9 = 7  =>  0 pairs (X) / G9 = 7  => 13 pairs (_)
A3,A8: 7.. / A3 = 7  =>  0 pairs (X) / A8 = 7  => 13 pairs (_)
* DURATION: 0:00:47.480792  START: 06:21:18.597184  END: 06:22:06.077976 2017-05-04
* CP COUNT: (28)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,B6,B7,C2,C3,E8,G1,G4,H9,I2,I3)
* .93675.28.8.13967..6.84293..78561.933152948676.9387...8..7.63.9.5.9.3.8.93.4.8...
* PAIR A1: 1,4 COL A
A8: 1,4,2,7                              # reduction candidate for 1,4
A8: 1,4 => CTR
* 493675128582139674761842935278561493315294867649387...8247.63.915.92378693.4.8...
A8: 2,7                                  # 13 pairs
* PAIR C2: 2,4 BLK 1
A2: 2,4,5                                # reduction candidate for 2,4
A2: 2,4 => CTR
* 193675428.8.13967556784293147856129331529486762938751484.7.635975.9.3.8.93.4.87..
A2: 5 => SOLVED
* 493675128582139674167842935278561493315294867649387512821756349754913286936428751
* PAIR C2: 2,4 COL C
C7: 2,4,1                                # reduction candidate for 2,4
C7: 2,4 => CTR
* .9367512828413967..6.84293..78561.933152948676.93875418427.63.9.5.9.3.8.93.4.8...
C7: 1                                    # 16 pairs
C8: 2,4,1,6,7                            # reduction candidate for 2,4
C8: 2,4                                  # 17 pairs
* PAIR C3: 1,7 BLK 1
A3: 1,7,5                                # reduction candidate for 1,7
A3: 1,7 => SOLVED
* 493675128582139674167842935278561493315294867649387512821756349754913286936428751
A3: 5 => CTR
* 193675428.8.13967556784293147856129331529486762938751484.7.635975.9.3.8.93.4.87..
* PAIR C3: 1,7 COL C
C8: 1,7,2,4,6                            # reduction candidate for 1,7
C8: 1,7 => CTR
* .93675128.8.139674.6.842935.78561.933152948676.93875..8.47.63.9.5.9234869364.87.2
C8: 2,4,6                                # 12 pairs
C9: 1,7,2,6                              # reduction candidate for 1,7
C9: 1,7 => CTR
* .9367512828413967..6.84293..78561.933152948676.93875418427.63.9.569.3.8293.428.56
C9: 2,6                                  # 14 pairs
* PAIR G1: 1,4 COL G
G6: 1,4,2,5                              # reduction candidate for 1,4
G6: 1,4 => CTR
* .93675.28.8.13967..6.84293..78561.93315294867649387152821756349.5.913.8.93.4.851.
G6: 2,5                                  # 13 pairs
G8: 1,4,2,7                              # reduction candidate for 1,4
G8: 1,4 => CTR
* .93675.28.841396755678429314785612933152948676293875..84.7.63.9.5.9.3.8.93.4.87..
G8: 2,7                                  # 13 pairs
* PAIR I2: 4,5 ROW 2
A2: 4,5,2                                # reduction candidate for 4,5
A2: 4,5 => SOLVED
* 493675128582139674167842935278561493315294867649387512821756349754913286936428751
A2: 2 => CTR
* .93675.28284139675567842931478561293315294867629387..484.7.63.975.9.348.93.4.8...
* PAIR I3: 1,5 ROW 3
A3: 1,5,7                                # reduction candidate for 1,5
A3: 7 => CTR
* .93675.28582139674761842935.78561.933152948676.9387...8.47.63.915.9234869364.87.2
A3: 1,5                                  # 13 pairs
* PAIR A4: 2,4 COL A
A2: 2,4,5                                # reduction candidate for 2,4
A2: 2,4 => CTR
* 193675428.8.13967556784293147856129331529486762938751484.7.635975.9.3.8.93.4.87..
A2: 5 => SOLVED
* 493675128582139674167842935278561493315294867649387512821756349754913286936428751
A8: 2,4,1,7                              # reduction candidate for 2,4
A8: 2,4 => CTR
* .93675.28.8.13967.761842935.78561.933152948676.9387...8..7.63.9.5.9.3.8.93.4.8...
A8: 1,7                                  # 13 pairs
* PAIR B6: 2,4 ROW 6
G6: 2,4,1,5                              # reduction candidate for 2,4
G6: 2,4 => CTR
* .93675128.8.139674.6.842935.78561.93315294867649387251821756349.5491378.93.4.851.
G6: 1,5                                  # 13 pairs
I6: 2,4,1                                # reduction candidate for 2,4
I6: 2,4 => SOLVED
* 493675128582139674167842935278561493315294867649387512821756349754913286936428751
I6: 1 => CTR
* 493675128582139674.6.84293527856149331529486764938725182.756349.549.378693.4.8...
* PAIR G4: 2,4 BLK 6
G6: 2,4,1,5                              # reduction candidate for 2,4
G6: 2,4 => CTR
* .93675128.8.139674.6.842935.78561.93315294867649387251821756349.5491378.93.4.851.
G6: 1,5                                  # 13 pairs
I6: 2,4,1                                # reduction candidate for 2,4
I6: 2,4 => SOLVED
* 493675128582139674167842935278561493315294867649387512821756349754913286936428751
I6: 1 => CTR
* 493675128582139674.6.84293527856149331529486764938725182.756349.549.378693.4.8...
* PAIR G4: 2,4 COL G
G8: 2,4,1,7                              # reduction candidate for 2,4
G8: 2,4 => SOLVED
* 493675128582139674167842935278561493315294867649387512821756349754913286936428751
G8: 1,7                                  # 13 pairs
* PAIR B7: 2,4 BLK 7
C7: 2,4,1                                # reduction candidate for 2,4
C7: 2,4 => CTR
* .9367512828413967..6.84293..78561.933152948676.93875418427.63.9.5.9.3.8.93.4.8...
C7: 1                                    # 16 pairs
A8: 2,4,1,7                              # reduction candidate for 2,4
A8: 2,4 => CTR
* .93675.28.8.13967.761842935.78561.933152948676.9387...8..7.63.9.5.9.3.8.93.4.8...
A8: 1,7                                  # 13 pairs
C8: 2,4,1,6,7                            # reduction candidate for 2,4
C8: 2,4                                  # 17 pairs
* PAIR E8: 1,2 BLK 8
E7: 1,2,5                                # reduction candidate for 1,2
E7: 1,2 => CTR
* .93675128.8413967..6.84293..78561.933152948676.938754184.7.6359.5.9.3.8.93.458.1.
E7: 5                                    # 14 pairs
E9: 1,2,5                                # reduction candidate for 1,2
E9: 1,2                                  # 14 pairs
* PAIR E8: 1,2 ROW 8
A8: 1,2,4,7                              # reduction candidate for 1,2
A8: 1,2 => CTR
* 493675128582139674761842935278561493315294867649387...8247.63.915.92378693.4.8...
A8: 4,7                                  # 13 pairs
C8: 1,2,4,6,7                            # reduction candidate for 1,2
C8: 1,2 => CTR
* 493675128.82139674167842935278561.933152948676.93875..8..7.63.975.9.34869364.87.2
C8: 4,6,7                                # 12 pairs
G8: 1,2,4,7                              # reduction candidate for 1,2
G8: 1,2                                  # 16 pairs
I8: 1,2,4,6                              # reduction candidate for 1,2
I8: 1,2 => CTR
* 493675128.82139674167842935278561.933152948676.9387...8..7.63.97569.348.93.4.87.6
I8: 4,6                                  # 13 pairs
* PAIR H9: 1,5 BLK 9
H7: 1,5,4                                # reduction candidate for 1,5
H7: 1,5 => CTR
* .93675.28.841396755678429314785612933152948676.9387.4.84.7.63.9.5.9.3.8.93.4.8...
H7: 4 => SOLVED
* 493675128582139674167842935278561493315294867649387512821756349754913286936428751
G9: 1,5,2,7                              # reduction candidate for 1,5
G9: 1,5 => CTR
* .93675.28.8.13967.761842935.78561.933152948676.9387...8..7.63.915692378.9374.8..6
G9: 2,7                                  # 14 pairs
* PAIR H9: 1,5 ROW 9
E9: 1,5,2                                # reduction candidate for 1,5
E9: 2 => SOLVED
* 493675128582139674167842935278561493315294867649387512821756349754913286936428751
E9: 1,5                                  # 16 pairs
* PAIR H9: 1,5 COL H
H6: 1,5,4                                # reduction candidate for 1,5
H6: 1,5 => SOLVED
* 493675128582139674167842935278561493315294867649387512821756349754913286936428751
H6: 4 => CTR
* .93675128.8413967..6.84293..78561.933152948676.938754184.7.63.9.5.9.3.8.93.4.8...
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-105-base-pr-000.dot
* REASONING
* DIS # A8: 1,4 => CTR => A8: 2,7
* DIS # A2: 2,4 => CTR => A2: 5
* PRF # A2: 5 => SOL
* DIS # C7: 2,4 => CTR => C7: 1
* PRF # A3: 1,7 => SOL
* DIS # A3: 5 => CTR => A3: 1,7
* DIS # C8: 1,7 => CTR => C8: 2,4,6
* DIS # C9: 1,7 => CTR => C9: 2,6
* DIS # G6: 1,4 => CTR => G6: 2,5
* DIS # G8: 1,4 => CTR => G8: 2,7
* PRF # A2: 4,5 => SOL
* DIS # A2: 2 => CTR => A2: 4,5
* DIS # A3: 7 => CTR => A3: 1,5
* DIS # A2: 2,4 => CTR => A2: 5
* PRF # A2: 5 => SOL
* DIS # A8: 2,4 => CTR => A8: 1,7
* DIS # G6: 2,4 => CTR => G6: 1,5
* PRF # I6: 2,4 => SOL
* DIS # I6: 1 => CTR => I6: 2,4
* DIS # G6: 2,4 => CTR => G6: 1,5
* PRF # I6: 2,4 => SOL
* DIS # I6: 1 => CTR => I6: 2,4
* PRF # G8: 2,4 => SOL
* DIS # C7: 2,4 => CTR => C7: 1
* DIS # A8: 2,4 => CTR => A8: 1,7
* DIS # E7: 1,2 => CTR => E7: 5
* DIS # A8: 1,2 => CTR => A8: 4,7
* DIS # C8: 1,2 => CTR => C8: 4,6,7
* DIS # I8: 1,2 => CTR => I8: 4,6
* DIS # H7: 1,5 => CTR => H7: 4
* PRF # H7: 4 => SOL
* DIS # G9: 1,5 => CTR => G9: 2,7
* PRF # E9: 2 => SOL
* PRF # H6: 1,5 => SOL
* DIS # H6: 4 => CTR => H6: 1,5
* CNT  35 HDP CHAINS /  58 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,B6,B7,C2,C3,E8,G1,G4,H9,I2,I3)
* .93675.28.8.13967..6.84293..78561.933152948676.9387...8..7.63.9.5.9.3.8.93.4.8...
* PAIR A1: 1,4 COL A
A8: 1,4,2,7                              # reduction candidate for 1,4
A8: 1,4 => CTR
* 493675128582139674761842935278561493315294867649387...8247.63.915.92378693.4.8...
* PAIR RESTART
* PAIR C2: 2,4 BLK 1
A2: 2,4,5                                # reduction candidate for 2,4
A2: 2,4 => CTR
* .93675.28.8.139675567842931.78561.933152948676.938751.8..7.63497549.3186936418752
A2: 5 => SOLVED
* 493675128582139674167842935278561493315294867649387512821756349754913286936428751
* DURATION: 0:00:05.085684  START: 06:23:01.795277  END: 06:23:06.880961 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-105-base-pr-001.dot
* REASONING
* DIS # A8: 1,4 => CTR => A8: 2,7
* DIS A8: 2,7 # A2: 2,4 => CTR => A2: 5
* PRF A8: 2,7 + A2: 5 => SOL
* STA A8: 2,7 + A2: 5
* CNT   3 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 105

solution: 493675128582139674167842935278561493315294867649387512821756349754913286936428751
info: 1621     FNBHWXY  S8.f     24487

http://www.sfsudoku.com/su17ExtremeDiff500.txt from http://www.minimumsudoku.com/

Solution

position: 493675128582139674167842935278561493315294867649387512821756349754913286936428751 solved
Solution

See section Pair Reduction for the HDP chains leading to this result.

Appendix: Full HDP Chains

A1. Pair Reduction Analysis

Full list of HDP chains traversed:

* DIS # A8: 1,4 => CTR => A8: 2,7
* INC # A8: 2,7 => UNS
* DIS # A2: 2,4 => CTR => A2: 5
* PRF # A2: 5 => SOL
* DIS # C7: 2,4 => CTR => C7: 1
* INC # C7: 1 => UNS
* INC # C8: 2,4 => UNS
* PRF # A3: 1,7 => SOL
* DIS # A3: 5 => CTR => A3: 1,7
* DIS # C8: 1,7 => CTR => C8: 2,4,6
* INC # C8: 2,4,6 => UNS
* DIS # C9: 1,7 => CTR => C9: 2,6
* INC # C9: 2,6 => UNS
* DIS # G6: 1,4 => CTR => G6: 2,5
* INC # G6: 2,5 => UNS
* DIS # G8: 1,4 => CTR => G8: 2,7
* INC # G8: 2,7 => UNS
* PRF # A2: 4,5 => SOL
* DIS # A2: 2 => CTR => A2: 4,5
* INC # A3: 1,5 => UNS
* DIS # A3: 7 => CTR => A3: 1,5
* DIS # A2: 2,4 => CTR => A2: 5
* PRF # A2: 5 => SOL
* DIS # A8: 2,4 => CTR => A8: 1,7
* INC # A8: 1,7 => UNS
* DIS # G6: 2,4 => CTR => G6: 1,5
* INC # G6: 1,5 => UNS
* PRF # I6: 2,4 => SOL
* DIS # I6: 1 => CTR => I6: 2,4
* DIS # G6: 2,4 => CTR => G6: 1,5
* INC # G6: 1,5 => UNS
* PRF # I6: 2,4 => SOL
* DIS # I6: 1 => CTR => I6: 2,4
* PRF # G8: 2,4 => SOL
* INC # G8: 1,7 => UNS
* DIS # C7: 2,4 => CTR => C7: 1
* INC # C7: 1 => UNS
* DIS # A8: 2,4 => CTR => A8: 1,7
* INC # A8: 1,7 => UNS
* INC # C8: 2,4 => UNS
* DIS # E7: 1,2 => CTR => E7: 5
* INC # E7: 5 => UNS
* INC # E9: 1,2 => UNS
* DIS # A8: 1,2 => CTR => A8: 4,7
* INC # A8: 4,7 => UNS
* DIS # C8: 1,2 => CTR => C8: 4,6,7
* INC # C8: 4,6,7 => UNS
* INC # G8: 1,2 => UNS
* DIS # I8: 1,2 => CTR => I8: 4,6
* INC # I8: 4,6 => UNS
* DIS # H7: 1,5 => CTR => H7: 4
* PRF # H7: 4 => SOL
* DIS # G9: 1,5 => CTR => G9: 2,7
* INC # G9: 2,7 => UNS
* INC # E9: 1,5 => UNS
* PRF # E9: 2 => SOL
* PRF # H6: 1,5 => SOL
* DIS # H6: 4 => CTR => H6: 1,5
* CNT  58 HDP CHAINS /  58 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A8: 1,4 => CTR => A8: 2,7
* DIS A8: 2,7 # A2: 2,4 => CTR => A2: 5
* PRF A8: 2,7 + A2: 5 => SOL
* STA A8: 2,7 + A2: 5
* CNT   3 HDP CHAINS /   2 HYP OPENED